Capacitive sensors are widely used in the field of human-machine interaction of electronic products. Specifically, a capacitance (or referred to as a base capacitance or an initial capacitance) is formed between a detection electrode and ground. When a conductor (such as a finger) approaches or touches the detection electrode, a capacitance between the detection electrode and the ground changes. By detecting a variation of the capacitance, information that the conductor approaches or touches the detection electrode can be acquired, so as to determine user operation. However, since the base capacitance tends to be greater, and a capacitance variation caused when the conductor approaches or touches the detection electrode is less, sensitivity of an existing capacitance detection method is lower, and capacitance detection cannot be accurately performed.